Fair Value Measurements (Marketable Equity and Cash Equivalents (Classified as Available-for-sale) and Cost Method Investments) (Details) (Fair Value, Inputs, Level 1, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 42,404	$ 43,198
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses	0	0
Fair Value	42,404	43,198
Money market instruments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	22,520	22,519
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses	0	0
Fair Value	22,520	22,519
Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	19,884	20,679
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses	0	0
Fair Value	19,884	20,679
Cash and Cash Equivalents
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	40,987
Gross Unrealized Holding Gains	0
Gross Unrealized Holding Losses	0
Fair Value	40,987
Cash and Cash Equivalents and Restricted Cash
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		41,721
Gross Unrealized Holding Gains		0
Gross Unrealized Holding Losses		0
Fair Value		41,721
Short-term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,417	1,477
Gross Unrealized Holding Gains	0	0
Gross Unrealized Holding Losses	0	0
Fair Value	$ 1,417	$ 1,477